SK telecom files lawsuit to overturn hefty data breach fine

(Yonhap)

SK telecom has filed an administrative lawsuit seeking to overturn a 134.8 billion won ($91.7 million) fine imposed over a large-scale personal data breach involving SIM card information of roughly 23 million subscribers.

According to industry sources on Monday, SK telecom submitted the suit to the Seoul Administrative Court, requesting the cancellation of the fine imposed by the Personal Information Protection Commission.

Following an investigation into the breach, the commission said last year that data on 23.24 million users — including phone numbers, international mobile subscriber identity (IMSI) numbers and SIM authentication keys — had been leaked, citing insufficient security measures. The watchdog imposed a fine of 134.79 billion won, the largest penalty since the commission‘s launch.

SK telecom decided to pursue legal action one day before the deadline for filing a cancellation suit under administrative litigation law. The company is understood to view the fine as excessive, noting that it implemented compensation measures such as free SIM replacements and rolled out information security reforms, while no financial losses linked to the breach were confirmed.

A company official said SK telecom seeks a thorough judicial review of the commission’s decision.